Topics

1

General Mach Discussion / MPG Step size mystery

« on: October 14, 2013, 04:48:30 AM »

Hi All

I've only been playing with MACH3 for a short time now so please forgive me if this is documented somewhere I haven't found yet.

The problem I'm having is that the step size I get in step/velocity mode is independant of the step size set in the MPG jogging panel and seems to be 100x the resolution/min increment for that axis.

I've been unable to find anywhere that sets this multiple (x100) hence I'm confused.

The step or multistep modes work just as expected with the step size being that selected in the MPG step size box.


Is this adjustable ?

CS

2

General Mach Discussion / Lathe servo spindle setup/cal issue

« on: October 11, 2013, 07:42:35 PM »

So I now have my lathe with servo spindle running in some fashion although there is an issue I can't resolve in the way I would expect or that makes sense. Iam running an ESS and the latest version of MACH3 and all drives are running in step and direction command interface.

So when I configure this servo to operate as a rotary axis with the steps per unit I calculate, all works well. The servo is setup to accept 8192 steps per revolution with the appropriate 'electronic gear ratio' to compensate for the 40:56 reduction of the timing pulleys. So no problems there !

However, when setup as a spindle in MACH3 I cannot use the same steps per unit. I guess that I don't really understand what this value means. So rather than using 8192 counts/rev (I have assumed this is what it means ie counts per rev) I have to used approximately 9000 counts per rev to get the actual spindle to the correct speed.

So in summary, the whole system works fine when the servo spindle is setup as a rotary axis ie counts per unit all work as expected etc. There seems to be something wrong or I'm doing something wrong when setting up to run as a spindle....

Also, I have tried running the spindle cal tool and when I press cal, the spindle gets stopped immediately.

Any help most appreciated !

CS

3

Show"N"Tell ( Your Machines) / CZ300 Chinese Lathe conversion

« on: October 09, 2013, 08:05:11 PM »

Hi All,

I purchased a 2nd hand lathe from a good friend of mine many years ago now and always intended to convert it to CNC.

My profession is in the field of custom automated equipment design and build hence I started with a good idea of the fundamentals, however the mindset was a bit of a hinderance since I approached things as though it was a professional machine build and I didn't have the time or funding to match !

So eventually I revised my plans to be more pragmatic, since 13months ago we had a new baby daughter and live on a 12acre hobby farm hence my time is a little 'stretched'....

Architecture as follows :

CZ300 Chinese lathe as staring point
Spindle: Kollmorgen S614 Servostar Servo amplifier + Kollmorgen Goldline M-407-B-A3 motor  (good for 3200RPM, 50Nm peak torque)
X axis : Delta 400W Servo amplifier ASDA-AB, with Delta 400W servomotor : ECMA-C30604ES  60mm frame, 400W and 3000RPM, 10000 count/rev enc
Z axis : Delta 750W Servo amplifier ASDA-A+, with Delta 750W servomotor : ASMT07L250AK  80mm frame, 400W and 3000RPM, 10000 count/rev enc
PC: Embedded pico ATX ATOM core duo running XP embedded
Controller :  MACH3 (of course)
Interface : ESS + CM126 breakout board

Since I have a big strong servo for the spindle, I decided that it should be setup to run in position mode ie step&dir or similar so that it can be switched between being a spindle and a rotary axis.
This meant I am driving it with a timing belt to ensure no slippage.

X axis screw is a 5mm pitch 12mm OD ballscrew. This was a big challenge to fit within the crosslide and required significant modifications.

Z axis screw is a 5mm pitch 20mm unit with rather odd multi contact bearing arrangement. This was donated to the project by a good friend and came out of a large printing machine. It seems to work fine at this time but I suspect it will need to be 'upgraded' to a proper ballscrew in time.

Current performance numbers are :

Z axis : 0.5um resolution, accuracy not measured, max speed : 125mm/s or 7.5m/min, acceleration set to 0.5G
X axis : 0.427um resolution, accuracy not measured, max speed 208mm/s or 12.48m/min, acceleration 1G
Spindle/A axis : 11878.4 counts per rev, 2200RPM, 72Nm peak torque

Some pics attached (still not sure how to insert them inline)

Will post some images of the build process and video of it running shortly.

CS

4

SmoothStepper USB / Problem with ESS install

« on: January 28, 2013, 01:57:29 AM »

In the process of setting up an ESS to test on an XP system and am having issues connecting to it.

Neither connection from Mach3 with the plugin or using the Configurator tool is working.

I used wireshark to see what is going on and it seems that there is a path problem of some form since after the Configurator responds to the Boot request with a 'Boot Reply' it seems it is looking for "d:\a.bin" which does not exist.

Screen capture attached.

No firewall turned on
PC IP address fixed at : 10.9.9.1
PC Hardware : Fairly old IBM laptop (Thinkpad)

Thoughts ?

CS